Preparation of 3-carboalkoxy or 3-alkanoyl furans Patent #: 4025537
ApplicationNo. 05/963645 filed on 11/24/1978
US Classes:549/483, Having -C(=X)-, wherein X is chalcogen, bonded directly to the hetero ring549/486The carbon of the -C(=X)X- group is bonded directly at the 3-position of the hetero ring
ExaminersPrimary: Raymond, Richard L.
Attorney, Agent or Firm
International ClassesC07D 307/00 (20060101)
C07D 307/46 (20060101)
C07D 307/68 (20060101)
Foreign Application Priority Data1978-05-01 DE
ClaimsWhat is claimed is:
1. A process for the production of substituted furans of the general formula ##STR3## wherein R is a member of the group consisting of alkoxy radicals with 1-6 C-atoms, asubstituted aryloxy radical, an unsubstituted aryloxy radical, and an alkyl radical, R1 is an alkyl or aryl radical with 1-6 C-atoms, R2 and R3 respectively, or both, represent an alkyl radical with 1-6 C-atoms, and hydrogen, by reacting aβ-dicarbonyl compound with an α-chlorocarbonyl compound in the presence of a compound capable of combining with hydrochloric acid formed, the process being characterized in that the reaction is carried out in water at pH values between 2 and 7with addition of equimolar amounts of an alkaline earth carbonate and wherein to the reaction mixture 0.1-20 mols % are added of a substituted or unsubstituted mononitrogen compound calculated on the β-dicarbonyl compound.
2. The process according to claim 1, wherein R stands for a methoxy or ethoxy radical.
3. The process according to claim 1, wherein the alkyl radical is methyl.
4. The process according to claim 1, wherein the reaction is carried out at a pH value of 3.5-6.
5. The process according to claim 1, wherein 0.5-5 mol% of pyridine are added to the reaction mixture.
6. The process according to claim 1 wherein ground dolomite with a particle size below 5 mm is added as the alkaline earth carbonate.